The effect of modifying the combination of insulin with rat adipose cells on the intracellular levels of cyclic AMP.

Abstract

Isoprenaline (1 μmol/l) and glucagon (1 μmol/l) raised the levels of cyclic AMP in isolated adipose cells of the rat to a maximum after incubation for approximately 15 min. The effect of glucagon was impaired by pretreatment of adipose cells with trypsin (0.2 mg/ml and 2.0 mg/ml) and N ethylmaleimide (5 mmol/l). The β adrenergic receptor was insensitive to such forms of treatment. Insulin (430 μunits/ml) lowered the intracellular levels of cyclic AMP in adipose cells stimulated with isoprenaline (1 μmol/l) and glucagon (1 μmol/l). This effect was observed after incubation for 5 min. Pretreatment of cells with trypsin (0.2 mg/ml and 2.0 mg/ml) and N ethylmaleimide (0.5 and 5 mmol/l) abolished..